

where \(M_j\)  is the mass, \(\eta _j\)  drag coefficient, and \(K_j\)  the spring of each oscillator (for j=1,2). \(K_c\)  is the stiffness of the spring that connects two oscillators. \(F_2(t)\)  is the force that stimulates the system. The classical analyses of such coupled oscillators are available [1]}, [2]}. Despite the simplicity of the idea, the frequency dependence of the energy transfer between the two oscillators is rather complex [2]}.
